fn get_pool(
env: soroban_sdk::Env,
token_a: soroban_sdk::Address,
token_b: soroban_sdk::Address,
) -> Pool
fn create_pool(
env: soroban_sdk::Env,
token_a: soroban_sdk::Address,
token_b: soroban_sdk::Address,
reserve_a: i128,
reserve_b: i128,
)
fn swap_a_to_b(
env: soroban_sdk::Env,
token_a: soroban_sdk::Address,
token_b: soroban_sdk::Address,
amount_in: i128,
) -> i128
fn swap_b_to_a(
env: soroban_sdk::Env,
token_a: soroban_sdk::Address,
token_b: soroban_sdk::Address,
amount_in: i128,
) -> i128